Flexible ammunition machine gun feed



Jan. 1, 1946.

c. R. ELLIOTT 7 2,391,888

FLEXIBLE AMMUNITION MACHINE GUN FEED Filed June 13, 1942 Patented Jan. 1, 1946 FLEXIBLE AMMUNITIQN- MACHINE GUN FEED Carleton R. Elliott, Dayton, Ohio Application June 1-3, 1942,- SeriaLNol 446,902

(Granted under the act of March 3', 1883,. as

amended April 30, 1928; 3 70 03' G. 757)- 4 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty-thereon;

This invention relates to improvements in machine gun feeding mechanism particularly adapted for use with a machine gun mounted for elevation-al' movement such as employed in aircraft,

Heretofore it has been the practice to feed ammunition to a machine gunof the type mounted for elevational movement in a turret or the like on an aircraft-from a shallow ammunition container removabl'y secured to the gun, the container incorporating therewith a curved chute for guiding the ammunition from the container to the feedway of the gun. To permit ease of handling, each container holds only a small quantity of ammunition which must be replaced by a full container as soon as the ammunition is exhausted, which also requires the rethreading of the ammunition belt into the feed mechanism of the gun. Further the mass added to the gun by mounting the ammunition container and feed chute thereon has adetrimental effect onthe firing of the gun since it adds considerably tothe inertia of the gunframe, which when taken with the resilientcharacteristics of the recoil absorbingmechanism, limits the possible rate of the To overcome the difiiculties encountered with the prior artfeeding mechanisms, the present invention uses a single ammunition container mounted separate from the gun and adapted tocontain all of the ammunition intended to be fired from a single gun in a single belt preferably of the type in which the cartridges are interconnected by links. The ammunition belt after be ing withdrawn from the container is preferably passed over a-guide such as a rotatable toothed sprocket mounted separate from the gun, the am munition belt then being passed over a second guiding means of a similar character mounted independent of the gun and spaced laterally from the first guiding means. The ammunition belt passes from the second guiding means into the feedway or the gun.

The second guiding means is so mounted that it isfree to rotate about an axis parallel with theelevation axis of the gun and also to swivel about an axis at right angles thereto so that as the gun is elevated or depressed from a level position the secondguide will rotate in a correspond"- ing direction through approximately onevhalf the angle of rotation of theg-un and will also swivel transversely so that the ammunition belt can twistwithoutbinding and; enter the ieedway of the gun in' alignment therewith. By" this arrangement the gun is relieved of the major portion of the-weight of the ammunition and thus reduces the inertia of the gun which allows a greater rate of fire thereof, and feeding the ammunition from" a; single container eliminates changing ammunition boxes and rethreading the ammunition belt and allows clear access to the gun for clearing a jamb if the same should occur.

In some instances where space is limited the swivelled ammunition belt guide maybe employed as the sole guide interposed between the ammunitioncontainer and the feedway' of the gun and maybe supported by a ball type universal joint toallow angular movement of the guiding means in any plane and also to rotate about an axis parallel with the elevation axis of the associated machine gun.

It is therefore an object of the invention to provide, in an ammunition feed for a machine gun mounted for elevational movement, an ammunition container supported separate from the gun and a guiding means for a belt of ammunition withdrawn from the container andso mount-- ed as" to be angularly rotatable about an axis parallel with the axis of elevation of the gun,

A further object of the inventionis the'provision, in an ammunition belt feed for a machine gun mounted for elevational movement, of guiding means for the ammunition belt which will support a substantial portion of the weight thereof and the guiding means beingmounted-independ-- ent of the gun, the mounting being constructed and arranged to permit the guiding means to' swivel at least about two axes at right angles toeach other and one of the axes beingparallel to the elevational axis of the gun;

A further object of the invention is the pro-- vision in an ammunition. feed for a machine gun mounted for elevational movement, of an ammunition container mounted separate fromthe gun ofa first roller guiding means mounted separate from the. gunand adapted to guide anammunition belt thereover to a second roller guid ing means spaced-i laterally therefrom and over which the ammunition=belt passes tothe feedway oi the machine gun, each of the guiding means being supported separate from the gun and the second: guiding means being supported in a swivel mounting which permits angular movement thereof about axes respectively parallel" andperpendicula-r to the axis of elevational movement of the gun.

Other objects'and features of the inventionnot specifically enumerated abovewill appear byref Referring now to Fig. 1 the reference numeral I indicates a conventional type of machine gun such as employed on military aircraft and having j e an ammunition feedway Ia and mounting lugs 2 for securing the gun frame to shock absorbing springs or equivalent recoil absorbers such as indicated at 3 and 4. The recoil springs 3 and 4 are secured to an arm 5 having integrally formed therewith a gear sector 6, adapted to cooperate witha power drive, not shown, to cause elevational movement of the gun. The arm 5 is provided with a'bea'ring boss! oneither side thereof which 's'erves to mount the 'arm 5 for rotation about the axis :c'x of the spindle 8 which is supported in a fork 9 formed as an integral part of the column I which is secured to mounting structure (not shown) forming part of a rotatable gun turret or the like. Though only asingle gun is shown supported in the above described mounting, a similar gun (not shown) is secured to the other ends of the springs3. and 4.

The gun I is supplied with ammunition from a single container 12 which is supported independent of the gun and is of a size sufficient to contain'all of the ammunition to be fired by the gun I, the ammunition being arranged in a belt as generally indicated at l4 in which the individual cartridges l are interconnected by removable links {E jof well' known construction, to thereby form a flexible ammunition belt well'kn'own in the art. The container l2'is preferably positioned below and close to the plane of the gun and the ammunitionbelt l4 after withdrawal from the container passes through a roller guide generallyindicated by-the reference'character I8, which includes an'attachment member I 9 which is secured to the turret framework (not shown). The detail construction of the roller guide' I8 is the same, except in the means of support, as a'second roller guide now to be'described.

v The ammunition belt lt'after passing over the roller-guide I8 is passed through a second roller guide: generally indicated by' the-reference numeral Zfl which is spaced laterally from and slightly above the guide I 8. The detail construc tionof the guide ZBis illustrated in'Fig. 2 and as there illustrated is seen to comprise a pair of spaced end plates 2| secured in assembled relation by upper and lower-plates 22 welded thereto; the latterhaving edges smoothly rounded fOr guidanceof the ammunition belt and a mounting plate 23is welded to the side plates to which the mounting structure is applied. The side plates 2| are each provided with a bearing sleeve 24 threaded therein and adiustably secured by a lock nut 2 5, a spindle 25"being rotatably mounted in the bearing sleeves'2'4. The spindle has mounted thereon in spaced relation, a: pair of" sprocket toothed guides 21, for supporting the case of the cartridges and a roller 28 adapted to support the nose portion thereof. Oneiof th end plates 2| is provided with radially extending guide rollers 30 which engage the base of the cartridge cases in guiding relation. The guidew thus far described isidentical in construction with the guide I8, the latter being,

however, provided with a welded on attaching means I 9 previously noted.

The guide Zll'is provided with a mounting means comprising a flange 3| welded to the back plate 23 5 and provided with an integrally formed rearwardly extending bearing .spindle fl, which is rotatably journaledl in a, bearing hub 33 and the spindle being restrained against axial movement by means of a thrust washer 34 and retaining nut 35. The hub 33 is provided with integrally formed bearing extensions 36 into which vertical bearing 5 pins 31 extend, the pins 3'! being removably secured to a U-shaped bracket 38 which is welded to a mounting flange member 39, which in turn may be bolted to a structural member such as indicated by the reference numeral 40, forming for example a part of the gun turret (not shown). By means of the above described pivotal mounting structure'the guide 20 may rotate about the axis of spindle 32 indicated as 'J-y in Figs. 1 and 2' and also swivel about the vertical axis of bearing pins 31'indicated as axis 'zz in Figs. 1 and 2.

Operation The operation of the novel ammunition guiding means of Fig. l is as follows; an end. of the ammunition belt 14 is withdrawn from the container l2 and threaded through guides l3 and 20 into the feedway la of the machine gun I. If then the gun elevation is changed before or during. firing, the gun will be rotated about axis .r-'.'rof Fig. 1," which will create a torque or twisting moment on the cartridge belt between the gun feedway jla andthe guide 20 which torque will cause the guide 20 to rotate aboutthe axis y-y which'in turn will cause a twist in the ammunition belt M between the guide 20 and the'fixed guide I8 so that the total angular twist of the belt willbe' distributed over the whol length of the same between the gun feedway laand the guide l8. The guide 20 will rotate about axis 11-1; through an angle equal approximately toone half the angular change inelevation of the gun I. As the angle of elevation of the gun is changed, the'belt I4 is rotatedin ahorizontal planeto some extent and the provision for pivotalv movement of'the' guide 20 about the aides-12 ensures proper guidance without binding, for this condition and this provision for pivotal movement also care s'for the change in belt alignment: due to reciprocating movement of the gun caused by recoil. By using rollers in-theguides I B and 20 and laterally spacing the guide 20 irom'guide l8, as illustrated in Fig. 1, the major portion of-the weight of the ammunition belt isisupported independent'of the gun, thus not adding to its mass and the am-' munition .belt'is subject to rolling friction only,

in passing from the container to the gun feed way. i e0 It is, of course, to be understood; that where space limitations prevent the lateral spacing arrangement of the guide means as;illustrated in Fig. 1,-the stationary'guide l8 ma be eliminated and the ammunition belt 14 guided solely bya pivotally mounted guide suchas the guide Zflof \Vhere there is the possibility of considerable movement of the ammunition belt in a; vertical plane, a full universal mounting for the guide '20' may be provided as illustrated in Fig.3; in which the back plate 23 of 'the'guide 20' hassecured.

thereto as by welding, a-fla ge 4?, whichhas in tegrally formed therewith a rearwardly extending shouldered stem 43 on which is secured flfibfill'fi which serves as' a bearinathe ball being retained by a sleeve 45, lock washer 46 and a nut 41 secured on the threaded outer end portion 48 of the stem 43. The bearing ball 44 is journaled in a spherical bearing seat 50 formed in the separable support members and 52 which are retained in assembled relation by cap screws such as 53, between which members the ball 44 has universal movement. The support member 5| is provided with a mounting flange 54 by which the assembly is secured to a structural member of the gun turret such as the member 50 of Fig. 2. The provision of the full universal mounting of Fig. 3 allows the guide 26 to rotate about an axis parallel with the elevation axis of the gun and also to move simultaneously in the horizontal and verticalplanes. The operation of the guide is otherwise identical with that as above described with reference to Fig, l."

While roller guides have been disclosed in the drawing and are preferred because the minimize friction, it is to be understood that guides of the type in which the ammunition belt slides therethrough may be employed, provided that at least one of the guides is 50 supported that it is capable, at least, of angular motion about an axis parallel with the elevational axis of the gun.

While preferred forms of the invention have been illustrated and described, it will be apparent to those skilled in the art that other modifications and variations may be made therein falling within the scope of the invention as defined by the appended claims.

I claim:

1. The combination with a machine gun mounted for elevational orientation, an ammunition belt feed mechanism comprising a belt guide support spaced laterall a substantial distance from the gun and fixed relative to gun elevation, a belt guide from which the belt is fed to the gun, means mounting said guide on said support, a second belt guide below the first laterally spaced therefrom and mounted independently of the gun and constructed and arranged to guide the belt to the first mentioned guide, said mounting means of the first mentioned guide being so constructed and arranged as to allow said first guide, through the instrumentality of the belt, to be rotated upon an axis parallel to the elevational axis of the gun and to swivel upon an axis at right angles to said elevational axis in response to the forces on said guide occasioned by elevation of the gun.

2. In combination with a machine gun mounted for elevational orientation, an ammunition belt feed mechanism comprising a belt guide support spaced laterally a substantial distance from the gun and fixed relative to gun elevation, a belt guide from which the belt passes to the gun, means mounting said guide on said support, the mounting for said guide being so constructed and arranged as to allow said guide, through the instrumentality of the belt, to be rotated upon an axis parallel to the elevational axis of the gun and to swivel upon an axis at right angles to said elevational axis in response to the forces on said guide occasioned by elevation of the gun.

3. In combination with a machine mounted for elevational orientation, an ammunition belt feed mechanism comprising a belt guide support spaced laterally a substantial distance from the gun and fixed relative to gun elevation, a belt guide from which the belt is guided to the gun, means mounting said guide on said support including a universal joint allowing said guide, through the instrumentality of the belt, to be rotated upon an axis parallel to the elevational axis of the gun and to swivel upon an axis at right angles to said elevational axis in response to the forces on said guide occasioned by elevation of the gun.

4. In combination with a machine munition belt feed mechanism comprising a belt guide support spaced laterally a substantial distance from the gun and fixed relative to gun elevation, a sprocket tooth rotatable belt guide from which the belt passes to the gun, means mounting said guide on said support, a second guide below the first and spaced laterall a substantial distance therefrom and adapted to guide the belt to the first mentioned guide, the mounting of the first mentioned guide including a universal joint allowing said guide, through the instrumentality of the belt, to be rotated upon an axis parallel to the elevational axis of the gun and to swivel upon an axis at right angles to said elevational axis in response to the forces on said guide occasioned by elevation of the gun.

CARLETON R. ELLIOTT.

gun mounted for elevational orientation, an am-' 

